Photoelectric cell



April 27, 1943. E. KGRBER PHOTOELECTRIC CELL Filed Oct. 24. 1959METHLL/C 843E METALLIC Bfl$\ FLA TE [JG/Y7 FERMEQBLE COU/VTEE ELECTRODEFLA TE LIGHT JENSITIV JELE/V/UM /w 7144 L 1c ca /mum five/7.2 am

Emil Kdrber 41 Patented Apr. 27, 1943 PHOTOEIEC'IRIO CELL Emil Ktirber,Nuremberg, Germany; vested in the Alien Property Custodian ApplicationOctober 24, 1939, Serial No. 300,993 In Germany October 24, 1938 2Claims.

This invention relates to photo-electric cells, and more particularly tonew and useful methods of manufacturing blocking layer photo-electriccells.

It is a. known expedient in the art when block- 5 ductive metalliccompound which remains unafing layer photo-electric cells of thestack-type are fected by the reduction medium. concerned to place orform a layer of a semi-con- In making the choice among the metalliccomductive material on a metallic base plate or elecpounds which may beconsidered suitable for aptrode and to cover this layer with alight-permeplication onto the semi-conductice layer overlayablecounterelectrode of high electric conductivl ing the base plateelectrode, care must be taken ity; a blocking layer being formed betweenthe that such electrically non-conductive compound semi-conductor andthe light-permeable countogether with the semi-conductive layer does notterelectrode either in response to a suitable treatform any undesiredcompound or compounds ment of the superflcles of the semi-conductor, inwhich may obstruct or upset the efiect of the a chemical reactionbetween the counterelectrode 1 blocking layer. and the semi-conductor,or by an artificially ap- The essential improvement secured accordingplied film of insulation which stands in no genetic to the method ofthis invention over the heretorelationeither to the semi-conductionlayer or fore known methods resides in the fact that the to thecounterelectrode, the thickness of such uniformity of the resultingblocking layer photofllm being in the order of only a few molecules.electric cell and, hence, the adaptation with re- The present inventionhas for an object to pe t di rent service conditions may be 80V- providenew methods of manufacturing photome -at will by correspondinglydimensionin electric cells of the above-mentioned type, acthe thicknessof the non-conductive comp cording to which the production of such cellsmay and by governing t e r of penetration 0 the be considerablysimplified and the properties of reductive or disintegra n me m. theproduct resulting therefrom be essentially In applying the now disclosedmethod to blockimproved. ing layer photo-electric cells in whichselenium The manner in carrying out my invention and forms thesemi-conductive layer, the most satisfurther objects thereof will befully understood ac y results ha e been obta d by ev n from thefollowing description taken in conjuncmg a lay r f admium Oxide onto theselenium tion with the accompanying drawing; the Figs. 1 andsubsequently b p i the admium oxide and 2 thereof in stronglyexaggerated scale emy r to n s n hydro n which y r u on bodylng the samephoto-electric cell during difconverts the superficies 01 the cadmiumoxide inferent steps of the manufacturing process act0 allic cadmium.This reduction preferably cording to this invention. as may be p is edby ow discharge.

In realizing the skill of this invention, a semi- W i claimed is:conductive layer B overlaying a metallic base e m thod of m nufa urinblockin layplate A constituting one of the electrodes of thePhoto-electric cells which comprises. pp yi photo-electric cellstoheproduced, is coated, prefby p riz ion a thin layer of cadmium oxideerably by vaporizatiomwith athin layer C 1 40 on the light-sensitivesemi-conducting layer of s ltable electrically non-conductive metallicSelenium verlayi a metallic base plate. and compound, whereupon thesuperflcies of the laydisintegrating the cadmium xi under he iner 0 isconverted by reduction into the metal fluence of nascent hydr e formingthe constituent of the metallic com- 2. The method of manufacturingphoto-elecpound as shown in Fig. 2, in which C" denotes trio cellshaving ablocking layer which comprises. the substantially pure metalliclayer or countercoating a conductive base plate with a lightsenelectrode and 0' indicates the remainder of the t ve ayer of seenium. applyin onsaid selenium non-conductive compound which isunaffected layer a h l yer of cadm um oxide and reducby the reductionmedium and which forms the ing the surface of said cadmium oxide layerby blocking layer of the cell. This expedient inblew!!! it to the action01 mt r m volves the beneficial advantage that, in addition a to theformation of a highly conductive and uniformly distributedlight-permeable counter-electrode, a blocking layer is simultaneouslyformed by the lower surface of mm-xbimm.

the electrically non-con-

